1. Field of the Invention
This invention relates to a device and related Process for measuring the range of cervical motion of a patient about three axes of rotation, and forward head posture.
2. Description of the Prior Art.
Several devices have been used to measure the range of cervical motion. Typically, such devices have utilized an angle finder and/or compass detachably secured to the human body through the use of a belt or strap to obtain the necessary measurements.
U.S. Pat. No. 4,485,825 to Domjan et al. discloses what is referred to as an arthrospinometer having an inclinometer and a north-south-seeking compass carried in a housing pivotally mounted on a base plate. The base plate has a scale thereon and an indicator is provided for indicating on the scale the degree of rotation relative to the base plate. There is also a scale for indicating the amount of rotation of the inclinometer and compass relative to the housing and this scale is rotatable relative to the housing about a common third axis. The base plate has a suction cup attached to its bottom side in order to secure the device to a portion of the human body. Such a method of securing the device to the human body does not facilitate the making of reproducible measurements as standardized placement and positioning are difficult.
The "Myrin" Goniometer produced by LIC Rehab Care utilizes an inclination needle and compass to indicate degree of rotation. The Myrin Goniometer is strapped to the body to take readings about a variety of joints. Reproducibility of data is very difficult as there are no established reference landmarks. Also, the Myrin Goniometer does not allow precise orientation of the inclination needle and compass as only the strap is used in mounting, making standardized measurements very difficult to reproduce for an objective comparison.
Other devices have been designed for measuring the range of cervical motion. In particular, U.S. Pat. No. 2,565,381 to Leighton discloses a device having a weighted pointer mounted within a housing having a rotatable calibrated dial. The device is attached to the body on one side of a joint and the weighted pointer is used to measure range of motion about the joint. U.S. Pat. No. 3,429,052 to Hembd et al. discloses a similar device which is dampened to reduce the oscillation of the weighted pointer which occurs in the Leighton device. Neither of these devices permits the making of range of motion measurements in more than one plane without having to reattach the device at a new position on the body. In addition, the data obtained would likely not be reproducible as no predesignated landmarks are established.
Other methods used for obtaining range of motion measurements have used a more mechanical approach. For example, U.S. Pat. No. 1,590,499 to Cozad discloses a device which may be attached to a human arm across the elbow as the arm is flexed or extended. Range of motion measurements are taken through the use of a protractor mounted on the device and a pointer which moves relative to the movement of the arm. Devices of this type are difficult to use in obtaining objective range of cervical motion measurements. Also, such mechanical devices are not conducive to obtaining reproducible data concerning range of cervical motion.
Various devices have been mounted on eyeglass type frames in order to obtain vision related measurements. For example, U.S. Pat. Nos. 2,491,312 to Henry et al. and 2,677,894 to Belgard disclose devices for taking ophthalmic measurements. The devices are designed to take measurements which facilitate the proper positioning of an eyeglass lens in front of the pupil. Such devices are of particular value to those patients wearing bifocal lenses. U.S. Pat. No. 4,328,620 to Mack et al. discloses a device which utilizes an eyeglass type frame to properly position an apparatus which registers the movements of the lower jaw with reference to the skull. The Mack device, however, is not capable of obtaining range of cervical motion measurements.
U.S. Pat. No. 4,586,515 to Berger shows a system for measuring motion in three dimensions, and U.S. Pat. No. 2,501,745 to Sherman shows a device for measuring angular movements including a level assembly for indicating a level condition.
Additional art of interest includes the following:
______________________________________ Country Patent No. Inventor ______________________________________ U.S. 3,614,950 Rabey U.S. 4,279,260 Stump U.S. 4,528,990 Knowles U.S. 4,444,204 Bryant et al Germany 3317918 Gross France 1534545 Kurose ______________________________________
Cervical region pathology is a common problem in humans with the instance increasing with age. A major symptom or sign of pathology is loss of motion in one or more planes of movement, and associated pain. Measurement of cervical motion of patients during the course of a therapeutic regimen provides objective data on the benefits of the selected treatment approach. Standardization of a protocol for measuring the motions of flexion/extension, lateral or side bending and rotation, and head and neck posture is a prerequisite to satisfactory use of objective and comparative measurements of cervical range of motion, which in turn permits objective evaluation of the theraputic regime.
An added feature is the adaptation that allows for measuring forward head posture. The therapeutic intervention is direct and correcting abnormalities restores limited motion, and also restores a more normal postural alignment.